MEASUREMENTS OF RELATIVE DIFFUSION COEFFICIENTS OF ARGON

A new method is used to measure relative diffusion coefficients as a function of temperature. The method permits an accuracy in the determination of the relative diffusion coefficient of 0.1%. The apparatus has been used for the first time to measure the selfdiffusion coefficient of argon in the temperature range from 235 K to 420 K. The derived potential parameters are for a Lennard-Jones 6-12 potential ε/k = = 135.5 K (± 1.5 K); for the modified Buckingham exp-6 potential ε/k = 128.5 K (± 0.75 K) with α equal to 14. These potential parameters have been compared with those obtained from other sources. © 1969.